Method and apparatus for retrofitting existing escalator systems

ABSTRACT

A method and apparatus for retrofitting existing escalator systems in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to escalators that are disposed between spaced-apart floors of a building. More particularly, the invention concerns novel method and apparatus for retrofitting existing escalator systems in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.

2. Discussion of the Prior Art

Prior art moving stairways or escalators typically include a support truss and a plurality of interconnected steps that travel in a loop within the truss to provide a continuous movement along a specified path. When the escalator assembly is appropriately mounted between the floors of a building, the ends of the truss rest on concrete or steel supports provided at each floor. Typically, the ends of the truss are not rigidly connected to the supports, but rather provision is made for some relative movement between the escalator assembly and the building structure to prevent catastrophic failures during an earthquake.

California Elevator Code adopted in October, 1998 includes seismic requirements for escalators that require that escalators be connected to their structural supports in such a way as to be capable of resisting specified code seismic forces and, at the time, be sufficiently free to move so that they will not be damaged by the relative movement, called “story drift”, of the building structure at the upper and lower landings of the building that are spanned by the escalator assembly.

Certain presently existing escalator assembly designs of which applicant is aware accommodate story drift by providing special connection mechanisms at each of the building landings that permit some limited movement between the escalator assembly and affixed-to building construction. One form of such prior art connection mechanism includes a first specially designed structural steel member that is interconnected with the escalator structure and a second specially designed, cooperating structural steel member that is interconnected with a fixed structural component of the building structure. More particularly, one of the first and second structural steel members is provided with a rib portion and the other is provided with a slot that receives the rib portion. With this construction the rib portion is free to move within the slot thereby permitting some limited motion between the escalator assembly and fixed structural components of the building structure.

One of the most effective systems for accommodating story drift is described in U.S. Pat. No. 6,637,580 issued to the present inventor. This patent describes an escalator or moving stairway that is constructed to accommodate oscillation and lateral displacement of a first story relative to a second story of a building between which the escalator or moving stairway extends such as that which may occur during an earthquake. The escalator includes novel telescoping connector mechanisms that are connected at one end to a structural support of the building and are connected at the other end to supporting trusses of the escalator in a manner to permit relative movement between the supporting trusses and the floors of the first and second stories of the building.

Another prior art escalator assembly design that has been proposed to accommodate story drift requirements caused by earthquakes is disclosed in U.S. Pat. No. 6,129,198 issued to Nusime. The Nusime patent discloses an escalator assembly wherein a first end of the carrier is provided with a bed support which is in turn supported upon a bed formed as part of the building construction by a resilient mounting element which provides damping for vibration and the like passing between the escalator and building construction. A second end of the carrier is similarly provided with a bed support, which is supported upon a fulcrum firmly mounted to the bed. The fulcrum may be in the form of a bolt upon which the bed support is detented. Damping means may be incorporated into the fulcrum construction.

The present invention contemplates a novel method and apparatus for retrofitting existing escalator systems in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method and apparatus for retrofitting existing escalator systems in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.

More particularly, an object of the present invention is to provide a method for retrofitting an escalator installation of the character having a truss support member and a building structure member for supporting the truss support member, the method comprising the steps of: drilling a through-bore in the trust support angle member; drilling a through-bore in the building structure member; and passing an elongated securement member through the drilled bores.

Another object of the invention is to provide a method of the aforementioned character in which the building support member comprises an I beam and in which the securement member comprises an elongated length of cable.

Another object of the invention is to provide a method of the aforementioned character in which the building support member comprises a reinforced concrete support member and in which the securement member comprises an elongated, threaded bolt.

Another object of the invention is to provide a method as described in the preceding paragraphs which can be inexpensively accomplished by relatively unskilled workmen.

Another object of the invention is to provide a retrofitting method of the character described that can be accomplished without having to make any major modifications to the escalator installation.

Another object of the invention is to provide a retrofitting method as described in the preceding paragraphs that can be accomplished without having to shutdown the escalator installation for any extensive period of time.

The foregoing as well as other objects of the invention can be accomplished by the method and apparatus described in paragraphs which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side-elevational view of a conventional, prior art escalator installation in which the escalator truss is supported by a steel I beam structural member.

FIG. 2 is a greatly enlarged, cross-sectional view of the area designated as 2-2 in FIG. 1.

FIG. 2A is a cross-sectional view, similar to FIG. 2, but illustrating one form of securement device of the present invention as it appears when installed in a conventional escalator installation, such as that shown in FIG. 1.

FIG. 3 is a greatly enlarged, cross-sectional view, similar to FIG. 2, but illustrating an alternate form of securement device of the present invention installed in a slightly different escalator installation.

FIG. 4 is a cross-sectional view taken along lines 4-4 of FIG. 3.

FIG. 5 is a cross-sectional view, similar to FIG. 2, but illustrating still another form of securement device of the present invention installed in still another, slightly different escalator installation.

FIG. 6 is a cross-sectional view of yet another form of securement device of the present invention installed in a slightly different escalator installation.

FIG. 7 is a cross-sectional view of still another form of securement device of the present invention of the character used in connection with a conventional escalator installation in which the escalator truss is supported by a reinforced concrete structural member.

FIG. 8 is a cross-sectional view of still another form of securement device of the present invention of the character used in connection with the securement of the escalator angular member with a reinforced concrete structural member.

FIG. 9 is a cross-sectional view of still another form of securement device of the present invention of the character used in connection with the securement of the escalator angular member with a reinforced concrete structural member.

FIG. 10 is a cross-sectional view taken along lines 10-10 of FIG. 9.

FIG. 11 is a cross-sectional view of yet another form of securement device of the present invention for use in connecting the escalator angular member with a steel I beam structural member.

FIG. 12 is a view taken along lines 12-12 of FIG. 11, partly broken away for better clarity.

FIG. 13 is a generally perspective view of the securement device illustrated in FIGS. 11 and 12, partly broken away for better clarity.

DESCRIPTION OF THE INVENTION

Referring to the drawings and particularly to FIG. 1, a typical form of prior art escalator installation is there shown. The escalator, generally designated as “E”, has a plurality of moving treads, means for moving the plurality of moving treads and a pair of spaced-apart supporting trusses for supporting the plurality of moving treads. Each of the trusses “T” has upper and lower ends disposed between a first floor F-1 of a building having a structural support SS-1 and a second floor F-2 of a building having a structural support SS-2. The upper end of the truss typically comprises a transverse structural steel angle member “A”, which is generally L-shaped in cross-section, while the structural support SS-2 may be a transverse I beam “B” (FIG. 2), or it may comprise a conventional concrete beam “CB” (FIG. 7). As illustrated in FIG. 2, angle member “A” is spaced-apart from structural support SS-2, or I beam “B” by a distance “D”. In a typical escalator construction, a plurality of shims “S” are positioned between angle member “A” and structural support SS-2. Shims “S” support but do not interconnect angle member “A” with structural support SS-2.

As will be described more fully in the paragraphs that follow, the methods of the invention concern various alternate approaches for retrofitting existing escalator systems of the character shown in the drawings in a manner to positively limit relative movement between the escalator and the spaced-apart floors of a building during an earthquake.

One retrofitting method of the invention, which is illustrated in FIG. 2A of the drawings, comprises a method for retrofitting an escalator installation having a truss support member in the form of an angle member “A” and a building structure member in the form of an I beam “B” for supporting the truss support member. This retrofitting method comprises the steps of: first forming, as by drilling, a through-bore 20 in the horizontally extending leg “H” of the truss support angle member. Next, a through-bore 22 is formed, as by drilling, through the horizontally extending upper leg web “U” of the building structure member “B”. This done, an elongated securement member, shown here as an elongated length of steel cable 24 having first and second spaced-apart ends 24 a and 24 b is passed through the bores 20 and 22. With the cable 24 in the position shown in FIG. 2A of the drawings, the ends 24 a and 24 b of the cable are suitably interconnected by a conventional cable connector 26 thereby securing the cable in position.

Another retrofitting method of the invention, which is illustrated in FIGS. 3 and 4 of the drawings, comprises a somewhat similar method for retrofitting an escalator installation having a truss support member in the form of an angle member “A” and a building structure member in the form of an I beam “B” for supporting the truss support member. In the escalator installation illustrated in FIGS. 3 and 4 of the drawings, it is to be noted that shims “S” are not positioned between the angle member and the building structure member. This latter retrofitting method comprises the steps of: first forming, as by drilling, a pair of horizontally spaced-apart through-bores 28 in the vertically extending leg “V” of the truss support angle member. Next, a pair of horizontally spaced-apart through-bores 30 is formed, as by drilling, through the vertically extending web “W” of the building structure member “B”. This done, an elongated securement member, shown here as an elongated length of steel cable 32 having first and second spaced-apart ends 32 a and 32 b is passed through the bores 28 and 30. With the cable 32 in the position shown in FIGS. 3 and 4 of the drawings, the ends 32 a and 32 b of the cable are suitably interconnected by a conventional cable connector 34, thereby securing the cable in position.

Still another retrofitting method of the invention is illustrated in FIG. 5 of the drawings. This latest method is also somewhat similar to the previously described methods for retrofitting an escalator installation having a truss support member in the form of an angle member “A” and a building structure member in the form of an I beam “B” for supporting the truss support member. It is to be noted that in the escalator installation illustrated in FIG. 5 of the drawings only one shim is positioned between the angle member and the building structure member and a conventional jack bolt “JB” is provided for adjusting the spacing between the structural members. It is also to be noted that in this construction, a connector plate 36 has been welded to the vertically extending web “W” of the building structure member “B”. This latest retrofitting method comprises the steps of: first forming, as by drilling, a through-bore 38 in the vertically extending leg “V” of the truss support angle member. Next, a through-bore 40 is formed, as by drilling, through the connector plate 36. This done, an elongated securement member, shown here as an elongated length of steel cable 42 having first and second spaced-apart ends 42 a and 42 b, is passed through the bores 38 and 40. With the cable 42 in the position shown in FIG. 5 of the drawings, the ends 42 a and 42 b of the cable are suitably interconnected by a conventional cable connector 44 thereby securing the cable in position.

Yet another retrofitting method of the invention is illustrated in FIG. 6 of the drawings. As before, this latest method comprises a method for retrofitting an escalator installation having a truss support member in the form of an angle member “A” and a building structure member in the form of an I beam “B” for supporting the truss support member. This latest retrofitting method comprises the steps of: first forming, as by drilling, a through-bore 46 in the horizontally extending leg “H” of the truss support angle member “A”. Next, a through-bore 48 is formed, as by drilling, through the horizontally extending upper leg web “U” of the building structure member “B”. This done, a securement member, shown here as a conventional threaded bolt 50 having a head portion 50 a and a threaded shank portion 50 b, is passed through the bores 46 and 48. With the bolt 50 in the position shown in FIG. 6 of the drawings, a conventional nut 50 c is threadably connected to bolt 50 and appropriately snugged down thereby securely interconnecting together the structural members “A” and “B”.

Turning now to FIG. 7 of the drawings, still another retrofitting method of the invention is there illustrated. This latest retrofitting method involves retrofitting an escalator installation of a slightly different character having a truss support member in the form of an angle member “A” and a building structure member in the form of a reinforced concrete structural support generally designated in the drawings as “RC”. This latest retrofitting method comprises the steps of: first forming, as by drilling, a through-bore 54 in the vertically extending leg “V” of the truss support angle member “A”. Next, a generally horizontally extending through-bore 56 is formed, as by drilling, through the vertically extending reinforced concrete post segment “P” of the reinforced concrete structure “RC”. This done, an elongated securement member, shown here as an elongated eye bolt 58, is passed through the bore 56. As indicated in FIG. 7, bolt 58 is threaded at one end 58 a and has at its opposite end an eye connector 58 b. With the bolt 58 in position within the reinforced concrete post segment and secured in position by a conventional nut 58 c, an elongated cable 60 having ends 60 a and 60 b is passed through bore 54 formed in leg “V” and through the opening in the eye connector 58 b. This done, the ends 60 a and 60 b of the cable are suitably interconnected by a conventional cable connector 62 thereby securing the cable in the position illustrated in FIG. 7.

Referring to FIG. 8 of the drawings, yet another retrofitting method of the invention is there illustrated. This retrofitting method involves retrofitting an escalator installation similar to that shown in FIG. 7, but in this latest retrofitting method a angularly extending through-bore 64 is formed, as by drilling, through the juncture of the vertically extending reinforced concrete post segment “P” and the horizontally extending beam segment “HS” of the reinforced concrete structure “RC”. After a bore 65 is drilled through the horizontal leg of the angle member “A”, an elongated securement member, shown here as an elongated eye bolt 66, is passed through the bore 64. As indicated in FIG. 8, bolt 66 is threaded at one end 66 a and has at its opposite end an eye connector 66 b. With the bolt 66 in position within the reinforced concrete structure and secured in position by a conventional nut 66c, an elongated cable 68 having ends 68 a and 68 b is passed through bore 65 formed in the horizontal leg and through the opening in the eye connector 66 b. This done, the ends 68 a and 68 b of the cable are suitably interconnected by a conventional cable connector 70 thereby securing the cable in the position illustrated in FIG. 8.

Turning to FIGS. 9 and 10 of the drawings, still another retrofitting method of the invention is there illustrated. This retrofitting method involves retrofitting an escalator installation similar to that shown in FIGS. 7 and 8, but in this latest retrofitting method a steel angle bracket 74 is initially affixed, as by welding, to the outer surface of the vertically extending leg “V” of the angle member “A” in the manner shown in FIG. 9. This done, an elongated, generally “T”-shaped connector bracket 78 having spaced-apart flange portions 78 a and 78 b is affixed, as by welding, to the lower surface of the horizontally extending leg 76 of the angle bracket 74 (FIG. 10). Flanges 78 a and 78 b are provided with a plurality of vertically spaced holes which are adapted to receive conventional anchor bolts 80. The next step in this latest method of the invention is to drill a plurality of vertically spaced-apart anchor bolt receiving bores in the reinforced concrete post segment “P”. Finally, connector bracket 78 is interconnected with the concrete post segment in a manner well understood by those skilled in the art, by means of the plurality of vertically spaced-apart anchor bolts 80 that are closely received within drilled bores formed in the reinforced concrete post segment “P”.

Turning to FIGS. 11, 12 and 13 of the drawings, yet another retrofitting method of the invention is there illustrated. This latter retrofitting method involves retrofitting an escalator installation somewhat similar to that shown in FIG. 1 of the drawings. More particularly, the method concerns retrofitting an escalator installation of the character shown in FIG. 11 having a truss support member in the form of an angle member “A” and a building structure member in the form of an I beam “B” for supporting the truss support member.

This latest retrofitting method comprises the steps of: attaching, as by welding, a first elongate bar 86 having a cross-bore 86 a to the vertically extending leg “V” of the truss support angle member. Next, a second bar 88 having a cross-bore 88 a is attached, as by welding, to the vertically extending web “W” of the building structure member “B”. This done, a threaded bolt 90 having first and second ends 90 a and 90 b is inserted through bore 86 a and a second threaded bolt 92 having first and second ends 92 a and 92 b is inserted through bore 88 a in the manner shown in FIG. 12. Using nuts 95 a and 95 b, a first plate 94 having an elongate bolt receiving slot 94 a and a drilled hole 94 b is next connected to the first ends 90 b and 92 b of bolts 90 and 92 in the manner shown in FIG. 12. This done, using nuts 97 a and 97 b, a second plate 98 having an elongate bolt receiving slot 98 a and a drilled hole 98 b is connected to the second ends 90 a and 92 a of bolts 90 and 92 in the manner shown in FIG. 12.

With the unique construction described in the preceding paragraph, angle member “A” along with bar 86 is movable horizontally relative to the I beam “B” to accommodate limited movement of the escalator relative to the supporting building structure during an earth quake.

Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims. 

1. A method for retrofitting an escalator installation having a truss support member and a building structure member for supporting the truss support member, said method comprising the steps of: (a) forming a through-bore in the truss support member; (b) forming a through-bore in the building structure member; and (c) passing an elongated securement member through said openings.
 2. The method as defined in claim 1 in which the building support member comprises an I beam and in which said securement member comprises an elongated length of cable.
 3. The method as defined in claim 1 in which said building support member comprises an I beam and in which said securement member comprises a threaded bolt.
 4. The method as defined in claim 1 in which the building support member comprises a reinforced concrete support member and in which said securement member comprises an elongated, threaded bolt.
 5. The method as defined in claim 1 in which the truss support member comprises an angle member having a horizontally extending leg and a vertically extending leg and in which the step of the method comprising forming a through-bore in the truss support member comprises the step of drilling a through-bore through said horizontally extending leg of said angle member.
 6. The method as defined in claim 1 in which the truss support member comprises an angle member having a horizontally extending leg and a vertically extending leg and in which the step of the method comprising forming a through-bore in the truss support member comprises the step of drilling a through-bore through said vertically extending leg of said angle member.
 7. The method as defined in claim 1 in which said building support member comprises an I beam having a connector plate affixed thereto and in which the step of the method comprising forming a through-bore in the truss support member comprises the step of drilling a through-bore through said connector plate of said I beam.
 8. A method for retrofitting an escalator installation having a truss support member comprising an angle member having a generally vertically extending leg and a generally horizontally extending leg and a building structure member for supporting the truss support member, the building structure member comprising an I beam having an upper flange, a lower flange and a web member interconnecting said upper and lower flange, said method comprising the steps of: (a) forming a through-bore through a selected one of the generally vertically extending legs and the generally horizontally extending legs of the truss support member; (b) forming a through-bore through a selected one of the upper flange and the web member of the building structure member; and (c) passing an elongated securement member through said openings.
 9. The method as defined in claim 8 in which said securement member comprises a threaded bolt.
 10. The method as defined in claim 8 in which said securement member comprises an elongated length of cable.
 11. The method as defined in claim 10 in which said elongated length of cable has first and second ends and in which said securement member further comprises a connector for interconnecting said first and second ends.
 12. A method for retrofitting an escalator installation having a truss support member and a reinforced concrete building structure member for supporting the truss support member, said method comprising the steps of: (a) forming a through-bore in the truss support angle member; (b) forming a through-bore in the building structure member; (c) passing an elongated bolt through said opening in said building structure member; and (d) interconnecting said elongated bolt with said truss support angle member.
 13. The method as defined in claim 12 in which said elongated bolt comprises a bolt having a threaded portion, and in which said method comprises the step of securing said elongated bolt to said building structure member using a nut threadably connected to said threaded portion of said elongated bolt.
 14. The method as defined in claim 12 in which said elongated bolt comprises an eye bolt having an eye portion and a threaded portion, and in which said method comprises the step of passing an elongated cable through said eye portion of said eye bolt and through said bore in the trust support angle member.
 15. A method for retrofitting an escalator installation having a truss support member comprising an angle member having a generally vertically extending leg and a generally horizontally extending leg and a building structure member for supporting the truss support member, the building structure member comprising an I beam having an upper flange, a lower flange and a web member interconnecting said upper and lower flange, said method comprising the steps of: (a) connecting a first elongate bar having a cross-bore to the vertically extending leg “V” of the truss support angle member; (b) connecting a second bar having a cross-bore to the vertically extending web “W” of the building structure member “B”; (c) inserting a first bolt having first and second ends through said cross-bore in said first elongate bar; (d) inserting a second bolt having first and second ends through said cross-bore in said second elongate bar; (e) connecting a first plate having an elongate bolt receiving slot and a drilled hole to said first ends of said first and second bolts; and (f) connecting a second plate having an elongate bolt receiving slot and a drilled hole to said second ends of said first and second bolts.
 16. The method as defined in claim 15 in which said first and second bolts are threaded and in which said first and second plates are connected to said bolts by nuts connected to said bolts. 